https://slproweb.com/products/Win32OpenSSL.html
Win64 OpenSSL v1.1.1g
C:\Program Files\OpenSSL-Win64\bin\openssl.exe
OpenSSL> pkcs12 -in filename.pfx -nocerts -out key.pem
Enter Import Password:
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
OpenSSL> rsa -in key.pem -out server.key
